The preliminary goal of this study is to design, construct and test an automatic sequential precipitation sampling instrument. Testing includes collection of sequential precipitation samples, analyzing them and trying to find the sources of environmental pollution. Proposed sequential sub-event sampler is composed of two parts; mechanic and electronic hardware. Mechanical part includes a stepped 100 ml sampler cups on it, and a metallic body. Electronic part is composed of digital and analog sensors, various electronic materials and a computer as the main controller of the system.